Interplay of Adolescents' and Parents' Mindsets of Socioeconomic Status on Adolescents' Stress-Related Outcomes

The reciprocity and variation of values and beliefs are dynamic features of the parent-child relationship. Parents and adolescents may hold congruent or incongruent views regarding the malleability of socioeconomic status (mindset of SES), potentially influencing adolescents' psychological and physiological stress outcomes, as reflected in stress perceptions and the hypothalamic-pituitary-adrenal (HPA) axis functioning. The current study investigated how patterns of parent-adolescent congruence and incongruence in mindset of SES were associated with adolescents' perceived stress and diurnal cortisol patterns four months later. A total of 253 adolescents (Mage = 12.60, 46.2% girls) and their parents (Mage = 40.09 years, 59.5% mothers) participated in this study. Polynomial regression analyses and response surface analyses showed that adolescents perceived lower levels of stress when they themselves or their parents reported a stronger growth mindset of SES. Additionally, adolescents with a stronger growth mindset of SES also exhibited a steeper diurnal cortisol slope. Moreover, parents' mindset significantly interacted with adolescents' mindset to influence adolescents' diurnal cortisol patterns such that when adolescents hold weaker growth mindset of SES, those with higher parental growth mindsets had significantly higher cortisol awakening response and steeper diurnal cortisol slope. Furthermore, adolescents who showed incongruence with their parents but had averagely stronger growth mindsets of SES reported a significantly steeper diurnal cortisol slope than those who had averagely weaker growth mindsets with their parents. The findings point to the beneficial impacts of the growth mindset of SES on stress-related outcomes among adolescents, as well as the significance of considering both parents' and adolescents' mindsets when exploring these associations.

The biology of hope: Inflammatory and neuroendocrine profiles in ovarian cancer patients

INTRODUCTION

Although the concept of hope is highly relevant for cancer patients, little is known about its association with cancer-relevant biomarkers. Here we examined how hope was related to diurnal cortisol and interleukin-6 (IL-6), a pro-inflammatory cytokine previously associated with tumor biology and survival in ovarian cancer. Secondly, we examined whether hope and hopelessness are distinctly associated with these biomarkers.

METHOD

Participants were 292 high-grade ovarian cancer patients who completed surveys and provided saliva samples 4x/daily for 3 days pre-surgery to assess diurnal cortisol. Blood (pre-surgery) and ascites were assessed for IL-6. Hope and hopelessness were assessed using standardized survey items from established scales (Center for Epidemiological Studies Depression Scale; Profile of Mood States, Functional Assessment of Cancer Therapy). Two hopeless items were z-scored and combined into a composite for analysis. Regression models related these variables to nocturnal cortisol, cortisol slope, plasma and ascites IL-6, adjusting for cancer stage, BMI, age, and depression.

RESULTS

Greater hope was significantly related to a steeper cortisol slope, β = -0.193, p = 0.046, and lower night cortisol, β = -0.227, p = 0.018, plasma IL-6, β = -0.142, p = 0.033, and ascites IL-6, β = -0.290, p = 0.002. Secondary analyses including both hope and hopelessness showed similar patterns, with distinct relationships of hope with significantly lower nocturnal cortisol β = -0.233,p = 0.017 and ascites IL-6, β = -0.282,p = 0.003, and between hopelessness and a flatter cortisol slope, β = 0.211, p = 0.031.

CONCLUSIONS

These data suggest a biological signature of hope associated with less inflammation and more normalized diurnal cortisol in ovarian cancer. These findings have potential clinical utility but need replication with more diverse samples and validated assessments of hope.

Biological sensitivity to adolescent-parent discrepancies in perceived parental warmth

Introduction

Parenting behaviors are formative to the psychological development of young people; however, parent and adolescent perceptions of parenting are only moderately correlated with each other. Whereas discrepant perceptions may represent a normative process of deindividuation from caregivers in some adolescents, in others a discrepancy might predict psychological maladjustment. The biological sensitivity to context model provides a framework from which individual differences in development can be estimated in adolescents whose perceptions of parenting diverge from those of their parents.

Methods

At baseline we obtained diurnal cortisol samples from US adolescents (M = 13.37 years of age, SD = 1.06) as well as parents' and adolescents' ratings of parental warmth; we obtained adolescent-reported symptoms of psychopathology at baseline and again at follow-up two years later (N = 108, 57.5% female). We estimated waking cortisol, cortisol awakening response, and daytime cortisol slopes using piecewise regression models.

Results

Lower adolescent than parent ratings of parental warmth predicted increased externalizing symptoms at follow-up. Higher waking cortisol and steeper cortisol awakening response and daytime slopes predicted increased internalizing symptoms at follow-up. Further, discrepant ratings of parental warmth interacted with cortisol awakening response and daytime slopes such that greater discrepancies predicted greater increases in externalizing symptoms in adolescents with steeper cortisol slopes.

Conclusions

These findings indicate that steeper changes in cortisol production throughout the day index a greater sensitivity to perceived parental warmth. Lower adolescent than parent ratings of parental warmth may represent dysfunction in the parental relationship rather than a normative process of deindividuation in adolescents with steeper diurnal cortisol slopes.

ADHD symptoms and diurnal cortisol in adolescents: The importance of comorbidities

BACKGROUND

Altered regulation of diurnal cortisol has been associated with both dimensional symptoms and clinical diagnoses of attention deficit-hyperactivity disorder (ADHD). Indeed, a recent meta-analysis suggests that lower diurnal cortisol output may be a biomarker of attention deficit-hyperactivity disorder (ADHD); importantly, however, the influence of psychiatric comorbidities on this association has not been characterized. Approximately two-thirds of children with ADHD have at least one co-occurring neuropsychiatric condition, and altered HPA-axis function has been implicated in many of these conditions. Using dimensional measures of psychopathology, we examined whether comorbid symptoms influence the association of ADHD symptoms with daily cortisol output.

METHODS

138 adolescents (ages 11-15 years) completed measures of symptoms of psychopathology and provided saliva samples over two days. We analyzed whether ADHD symptoms were related to morning, afternoon, and evening cortisol, the cortisol awakening response (CAR) and cumulative daily cortisol (area under the curve with respect to ground [AUCg]) while accounting for symptoms of three psychiatric disorders that are commonly comorbid with ADHD: conduct disorder (CD), anxiety, and depression. In sensitivity analyses, we included symptoms of oppositional defiant disorder (ODD) in place of CD symptoms.

FINDINGS

After controlling for symptoms of CD, anxiety, and depression, ADHD symptoms were associated significantly with higher cumulative diurnal cortisol (AUCg), morning cortisol, and afternoon cortisol. Symptoms of CD, anxiety and depression were not associated significantly with any cortisol metrics; however, in sensitivity analyses, ODD symptoms were associated with lower AUCg and morning cortisol.

DISCUSSION

Our findings highlight the distinct influence of ADHD and externalizing symptoms on cortisol output. Further work is needed to examine the specificity of altered HPA-axis activity as a biomarker of ADHD and to elucidate whether symptoms of ADHD differ in their association with diurnal cortisol as a function of their severity.

Child maltreatment and hypothalamic-pituitary-adrenal axis functioning: A systematic review and meta-analysis

Alterations in hypothalamic-pituitary-adrenal (HPA) axis and its effector hormone cortisol have been proposed as one possible mechanism linking child maltreatment experiences to health disparities. In this series of meta-analyses, we aimed to quantify the existing evidence on the effect of child maltreatment on various measures of HPA axis activity. The systematic literature search yielded 1,858 records, of which 87 studies (k = 132) were included. Using random-effects models, we found evidence for blunted cortisol stress reactivity in individuals exposed to child maltreatment. In contrast, no overall differences were found in any of the other HPA axis activity measures (including measures of daily activity, cortisol assessed in the context of pharmacological challenges and cumulative measures of cortisol secretion). The impact of several moderators (e.g., sex, psychopathology, study quality), the role of methodological shortcomings of existing studies, as well as potential directions for future research are discussed.

Psychological resilience and diurnal salivary cortisol in young adulthood

BACKGROUND

Adversity exposure and the negative psychological responses that often result have been linked with poor physical health outcomes and deteriorative physiological processes, like dysregulated circulating cortisol. Individuals exposed to early adversity who also demonstrate positive psychological functioning may be characterized as psychologically resilient, but few studies have evaluated whether psychological resilience may disrupt the health-damaging effects of adversity. We tested the hypothesis that among young adults exposed to early adversity, those who are psychologically resilient may manifest more normative diurnal cortisol patterns relative to those who experience more psychological distress.

METHODS

Data are from Growing Up Today Study I participants who provided information on psychological resilience and diurnal salivary cortisol (n = 916). Psychological resilience was derived from self-report questionnaires administered between 2007 and 2010, and salivary cortisol was obtained from saliva samples collected between 2011 and 2014. The predictor of interest, psychological resilience, was defined using two domains: (1) adversity exposure measured via a count of 7 potential psychosocial adversities experienced before age 18, and (2) psychological health in young adulthood measured via a composite score reflecting low psychological distress and high positive affect. The outcome was mean log-transformed diurnal salivary cortisol across 4 samples from one day. Linear regressions evaluated associations of adversity, psychological health, and their potential multiplicative interaction with mean diurnal log-transformed cortisol, adjusting for baseline socio-demographic variables and biological and behavioral factors from the day of saliva sampling.

RESULTS

Relatively few individuals with high adversity demonstrated positive psychological health. Both adversity exposure and psychological health were independently associated with mean log cortisol levels. Models stratified by lower versus higher adversity suggested complex relationships with cortisol, however the interaction between adversity and psychological health was not statistically significant. High adversity was associated with blunted cortisol levels, regardless of psychological health. Conversely, among those with lower adversity, overall levels of cortisol were higher and psychological health associated with more normative, lower cortisol levels.

CONCLUSIONS

Psychological resilience domains were independently associated with diurnal salivary cortisol in young adulthood. High burden of early adversity may disrupt the physiological stress system, while psychological health may be associated with more normative cortisol levels when adversity is low.

Effects of parental care and overprotection on adolescents' diurnal cortisol profiles

Parental bonding is a strong determinant of children's health. One of the proposed pathways through which parenting impacts children's health is by altering the functioning of stress response systems. The current study aims to investigate the associations between two types of parental bonding (care and overprotection) and functioning of hypothalamic-pituitary-adrenal (HPA) axis (i.e., diurnal cortisol secretion) in a sample of 255 healthy adolescents (46.3% girls; aged 11-14 years). Participants completed the Parental Bonding Instrument and provided eight cortisol samples across two consecutive days to assess patterns of diurnal cortisol secretion. Multilevel modeling and multiple linear regression were utilized to test the main effects and interactive effects of parental care and overprotection on adolescents' wakeup cortisol, cortisol awakening response, cortisol slope, and total cortisol secretion. Results showed that parental care was associated with higher cortisol levels at awakening, while parental overprotection was associated with lower cortisol levels at awakening. Parental overprotection, but not parental care, was associated with flatter cortisol slopes. No interactive effects between parental care and overprotection on cortisol parameters emerged. The current findings add to the existing literature on parenting behavior and HPA functioning by showing that parental care and overprotection differently regulated daily cortisol parameters implicated in health.

Unique and interactive associations of proactive and reactive aggression with cortisol secretion

The association between aggressive behaviors and diurnal cortisol levels has been debated over the past two decades, as some studies found a negative link between the two, whereas others reported no or a positive association. One possible explanation for these contradictory results is that past studies failed to distinguish between proactive (PROA) and reactive (REA) aggression. The present study examined the unique and joint associations of PROA and REA with three diurnal cortisol indicators: awakening levels, awakening response, and diurnal change. Participants were 542 youths (55.4% girls) followed longitudinally. Teachers evaluated aggressive behaviors when participants were in Grades 4 and 6. In Grade 8, participants provided four saliva samples (i.e., awakening, 30 min thereafter, late afternoon, and bedtime) on four collection days. Controlling for several confounders, multilevel regression analyses revealed an inverse relation between PROA and the CAR in boys who displayed lower or moderate levels of REA, but not in those who exhibited higher levels of REA. No associations emerged with other cortisol indicators. These results are consistent with reports of lower physiological activity in individuals with PROA and underscore the confounding influence of REA in the association between the CAR and proactive aggression.

Associations between social burden, perceived stress, and diurnal cortisol profiles in older adults: implications for cognitive aging

Stress can be a risk factor for mental and physical health. We investigated the role of social burden as a potential stressor in older age and its associations with cognitive aging (i.e., within the domains inhibition and cognitive flexibility of executive functioning). Eighty-three older adults (N = 38 male, mean age = 74.0 ± 5.7 years, body-mass index = 25.5 ± 4.1 kg/m²) aged 64 years or older participated. Cognitive flexibility and inhibition were assessed by means of a Trail-Making Test (TMT) and a Stroop task. Perceived levels of social burden and perceived stress in general were assessed via standardized questionnaires. Furthermore, diurnal cortisol profiles were assessed. Overall, older participants showed lower cognitive performance than the younger (both inhibition and cognitive flexibility; p < .044). However, this association did not remain significant when adjusting for multiple comparisons. Social burden was highly correlated with perceived stress, highlighting its importance as a stressor (p < .001). Furthermore, participants who reported higher levels of perceived stress showed lower performance in the TMT as a measure for cognitive flexibility (p < .001). Moreover, social burden was associated with cognitive flexibility, which was assessed by means of the TMT (p = .031). However, this association did not remain significant when using the adjusted α-level. Furthermore, we found that total diurnal cortisol output was a mediator for the relationship between age and inhibition, which was assessed by means of a Stroop task. At last, we found that the mediating role of cortisol interacts with social burden in the way that especially in younger age, high levels of social burden are associated with higher cortisol levels and, therefore, with lower cognitive performance. We conclude that it is important to consider social burden as an additional stressor in older age which is associated with cognitive aging.

Impact of loneliness on diurnal cortisol in youth

Loneliness is associated with multiple forms of psychopathology in youth. However, we do not yet know how loneliness gets "under the skin" in ways that may impact the long-term health and development of early adolescents. In particular, loneliness may influence youths' patterns of diurnal cortisol, an index of hypothalamic-pituitary-adrenal (HPA) axis functioning and a central predictor of health across the lifespan. The current severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2, or COVID-19) pandemic represents a salient period in which to study the consequences of loneliness, as recent work has provided evidence that the physical-distancing measures put in place to contain the virus have resulted in greater loneliness, particularly among youth. Thus, the current study aimed to examine the prospective association between loneliness during the COVID-19 pandemic and diurnal cortisol in early adolescents. We found that greater loneliness was associated with higher levels of cortisol at waking and a blunted cortisol awakening response (CAR). These results held even when controlling for covariates that can influence diurnal trajectories of cortisol. Critically, this pattern of HPA-axis functioning increases risk for adverse mental and physical health outcomes across adolescence and into adulthood. This study is the first to examine the prospective association between loneliness and diurnal cortisol in early adolescence, and the first to identify mechanisms that contribute to biological markers of distress during the COVID-19 pandemic. Findings underscore the importance of developing and distributing strategies to mitigate feelings of loneliness among youth.

Identifying diurnal cortisol profiles among young adults: Physiological signatures of mental health trajectories

Previous research has used cortisol, the major hormonal byproduct of the hypothalamic pituitary adrenal (HPA) axis system, to explore how environmental stressors influence daily physiological functioning. Most of the research focused on diurnal cortisol has examined specific cortisol markers, with little consideration of how different components of the diurnal pattern may co-occur. Morning level, cortisol awakening response (CAR), bedtime level, as well as the diurnal slope and total cortisol exposure throughout the day (area under the curve; AUC), are five common parameters of diurnal HPA axis functioning that have been individually linked to physical and mental health outcomes, with mixed results. The current study introduces a novel approach to capture heterogeneity in HPA axis activity by using latent profile analysis to generate empirically-derived, theoretically supported diurnal cortisol profiles based on all five indicators. We analyzed salivary cortisol data from 278 young adults during a time of heightened sociopolitical stress - the 2016 U.S. presidential election - and examined whether profiles differentially predicted mental health trajectories across six months. Findings suggest that a specific combination of cortisol parameters (i.e., flat slope, high AUC, and high CAR) may predict worse mental health risk over time. Overall, this work suggests that diurnal cortisol profiles likely reflect distinct physiological underpinnings with unique health consequences that may not be observed by studying individual cortisol parameters.

Perceived stress is linked to heightened biomarkers of inflammation via diurnal cortisol in a national sample of adults

Exposure to and perceptions of stress have been associated with altered systemic inflammation, but the intermediate processes by which stress links to inflammation are not fully understood. Diurnal cortisol slopes were examined as a pathway by which self-reported psychosocial stress is associated with inflammation [i.e., C-reactive protein (CRP), interleukin-6 (IL-6), fibrinogen, E-Selectin, and Intercellular Adhesion Molecule-1 (ICAM-1)] in a large sample of adults (the Midlife in the US study; N = 914; 55.9% female; aged 34-84 years). Structural equation modeling indicated that perceived psychological stress was associated with flattened diurnal cortisol slopes and flatter diurnal cortisol slopes were, in turn, associated with heightened inflammation in these cross-sectional analyses (index of indirect pathway, ω = 0.003, 95% CI [0.001, 0.004], ωSTD = 0.027; with covariates, ω = 0.001, [0.0002, 0.002], ωSTD = 0.011). A similar indirect effect was evident for self-reported traumatic life events (ω = 0.007, [0.004, 0.012], ωSTD = 0.030); however, inclusion of covariates (i.e., age, gender, race, ethnicity, body mass index, and other factors associated with physical health) accounted for this finding (ω = 0.001, [-0.001, 0.004], ωSTD = 0.005). These results support an allostatic load model of psychosomatic health, in which cortisol (along with other stress-responsive signaling molecules) is a necessary component for understanding links between stress exposure, perceived stress, and immune functioning.

Early childhood adversity and HPA axis activity in adulthood:The importance of considering minimal age at exposure

Early adversity (EA) modulates stress hormone secretion in mixed directions. The Accumulation Model suggests that the number of EA predicts patterns of cortisol dysregulations, while the Life Cycle Model of Stress highlights the importance of considering the timing at which EA began, given that brain regions sensitive to stress hormones follow distinct developmental trajectories. We aimed to test these two models in 85 healthy men and women, aged 21-40 years old who reported having been exposed to EA during childhood. Participants were grouped based on the number of EA events to which they were exposed during their lifespan (Accumulation Model) and the age of first exposure to EA (Life Cycle Model). Diurnal and stress-induced reactive cortisol secretion were measured in all participants. Results showed that although the number of EA was not associated with patterns of basal or reactive cortisol secretion, adults first exposed to EA between the ages of 3 and 7 - an important time window for amygdala development - showed greater cortisol awakening response and lower cortisol reactivity relative to those first exposed to EA before 3 or after 7. These results provide support for the Life Cycle Model of Stress and highlight the importance of considering minimal age at exposure to EA when assessing the effects of early adversity on patterns of cortisol secretion.

Couples' behavior during conflict in the lab and diurnal cortisol patterns in daily life

The current study tested whether positive and negative behaviors exhibited by couples during conflict interactions assessed in the laboratory are associated with individuals' diurnal cortisol patterns (i.e., circadian rhythms in cortisol across the course of the day) outside of the lab. Participants (N = 82) provided a total of 18 salivary cortisol samples over a 3-day period and came into the lab with their spouse to engage in two ten-minute dyadic conflict discussions. These videotaped interactions were coded to assess the intensity with which couples displayed various positive behaviors (e.g., humor, affection) and negative behaviors (e.g., defensiveness, frustration) during the conflict discussions. Multi-level modeling was used to examine the associations between couples' positive and negative behavior during conflict discussions and diurnal cortisol patterns in daily life. Results showed links between overall positive, but not negative, behaviors and diurnal cortisol patterns. Individuals who experienced more positive behaviors with their partner during the conflict discussion showed a steeper ("healthier") cortisol slope across the day in their daily lives. Exploratory analyses investigating the association between specific positive and negative behaviors and diurnal cortisol revealed that affection and scorn were associated with diurnal cortisol patterns in daily life. This research advances our understanding of the impact of social relationships on physical health from a biopsychosocial perspective and has implications for understanding how the ways in which couples resolve conflict are linked to health-related biological processes in daily life.

Evening salivary cortisol as a single stress marker in women with metastatic breast cancer

BACKGROUND

Flattened diurnal salivary cortisol patterns predict shorter subsequent survival with breast, lung, and renal cell carcinomas. The underlying cause of this flattened slope is undetermined, though it has been hypothesized to be secondary to a deficit in the amplitude of the circadian clock. To gain greater insight into the portions of the diurnal salivary curve that are associated with cancer survival, we examined (1) which points in the diurnal curve are predictive of the slope of the curve and (2) whether elevated evening cortisol levels alone are associated with reduced HPA-axis feedback inhibition (i.e., decreased sensitivity to the dexamethasone suppression test).

METHOD

We examined study hypotheses on adult women with advanced breast cancer (age = 54.3 ± 9.58 years; n = 99) using non-parametric Wilcoxon's rank-sum tests, Spearman correlation coefficients and an accuracy formula based on a confusion matrix. Cortisol was sampled five times per day for three consecutive days, with dexamethasone administered late on the second day.

RESULTS

Salivary cortisol concentrations did not vary between those with flat and steep slopes during the morning (p's > .05), but did vary in the evening (p's < 0.05). Furthermore, the concentration of the 2100h alone was 86% accurate in discriminating between individuals classified as having "flat" or "steep" slopes. Dexamethasone suppression was only associated with diurnal salivary cortisol slope (p = .0042).

CONCLUSIONS

Evening cortisol levels are a sensitive indicator flattened diurnal cortisol slope, suggesting evening cortisol may also be a useful predictor of breast cancer survival. Future research should focus on determining the causes of abnormally increased evening cortisol.

Impact of a social skills program on children's stress: A cluster randomized trial

BACKGROUND

Most preschool children in Western industrialized countries attend child care during the day while parents work. Studies suggest that child care may be stressful to young children, perhaps because they still lack the social skills to interact daily in a group setting away from parents. This gap in social abilities may be greater for children in lower-income families, who may face more adversity at home, with fewer resources and more social isolation.

METHODS

We conducted a cluster-randomized controlled trial in 2013-2014 to test whether a social skills intervention led by early childhood educators within the child care center could reduce diurnal cortisol levels to more typical patterns expected of children this age. We randomized 19 public child care centers (n = 361 children) in low-income neighborhoods of Montreal, Canada, to either: 1) the Minipally program - intervention group (n = 10 centers; 186 children), or 2) waiting list - control group (n = 9 centers; 175 children). Saliva samples for cortisol levels were collected 3 times/day, pre- and post-implementation. The Minipally puppet program consists of 2 workshops/month for 8 months for the development of social skills and self-regulation in 2-5-year-olds, with reinforcement activities between workshops. Educators received 2-days' training and 12 h' supervision in Minipally.

RESULTS

Linear mixed models for repeated measures revealed a significant interaction between intervention status and time of day of cortisol sampling (β = -0.18, p =  0.04). The intervention group showed patterns of decreasing diurnal cortisol secretion (β = -0.32, p < 0.01), whereas the control group showed increasing slopes (β = 0.20, p < 0.01). Moreover, family income was a moderator; children in lower-income families benefited most from the intervention.

CONCLUSION

Results suggest that a social skills training program, when integrated into a preschool education curriculum, can foster an environment more conducive to typical childhood patterns of cortisol secretion.

Peer victimization and diurnal cortisol rhythm among children affected by parental HIV: Mediating effects of emotional regulation and gender differences

The hypothalamic-pituitary-adrenal (HPA) axis activity has been demonstrated as one of the physiological mechanisms underlying the long-lasting effects of peer victimization on physical and mental health. However, the mechanisms linking peer victimization to dysregulations of HPA axis activity remain inadequately understood. The present study examined the potential mediating role of emotional regulation in the association between peer victimization and HPA axis activity in a large community-based sample of 645 children affected by parental HIV (Mage = 10.67 years, ranging from 8 to 15 years old). The three-level growth curve model revealed that higher peer victimization was associated with lower emotional regulation, which in turn was related to lower cortisol at awakening and more blunted diurnal slopes in girls, but not in boys. The findings highlight the protective effect of emotional regulation in relation to HPA axis activity in victimized children, particularly in girls.

Microaggressions and Diurnal Cortisol: Examining Within-Person Associations Among African-American and Latino Young Adults

PURPOSE

We examined the relations between African-American and Latino young adults' microaggressions and subsequent changes in weekly diurnal cortisol parameters (i.e., cortisol awakening responses, overall cortisol output (AUC), and diurnal slopes).

METHODS

Young adults (N = 53, M_age = 20years, SD = .90; 72% female) participated in a 4-week diary study in which they reported their weekly experiences of microaggressions and completed 2 days ofsaliva samples each week. Saliva samples were obtained at waking, 30-minutes after waking, and bedtime on each sampling day (six samples each week; 24 samples total). In line with an idiographic approach to stress, young adults' increases and decreases in microaggressions (relative to their own average) were linked to changes in cortisol parameters the following week.

RESULTS

Increases in microaggressions predicted greater AUC the subsequent week, controlling for gender, race, parental education, prior week's AUC, and weekly behavioral controls. Follow-up analyses of specific types of microaggressions indicated that experiences centered around criminality and second-class citizenship also related to increases in young adults' cortisol awakening responses the subsequent week. Microaggressions were unrelated to changes in diurnal slopes.

CONCLUSIONS

Microaggressions were linked to subsequent changes in diurnal cortisol among African-American and Latino young adults. Given the rigorous within-person design, findings point to the importance and impact of subtle forms of discrimination on young adults' hypothalamic-pituitary-adrenal axis activity, which is theorized to underlie health and well-being.

Classroom social experiences in early elementary school relate to diurnal cortisol levels

Social stress has been linked to altered hypothalamic-pituitary-adrenocorticol (HPA) axis activation. During elementary school, children can become exposed to negative peer relations, such as poor appraisal among classroom peers, which is considered a social stressor. However, little is known about the association between classroom peer appraisal and the physiological stress system in children. The goal of this study was to examine the association of peer acceptance and peer non-acceptance with diurnal cortisol concentrations in 222 children from 20 mainstream elementary schools (Mage=6.97years, SD=0.99, 55% boys) in the Netherlands. Saliva samples were collected at awakening, 30min post-awakening, at noon and at 8 pm during a weekend day. From these assessments, the Cortisol Awakening Response (CAR), diurnal cortisol concentration (AUC_g) and diurnal cortisol slope were calculated. Peer nominations of peer acceptance (being liked), and peer non-acceptance (being disliked) were collected across a one year interval. Associations were controlled for peer victimization, age, sex and SES and children's levels of emotional problems and behavioural problems. Results showed that low peer acceptance was associated with heightened diurnal cortisol concentration (i.e., heightened AUG_g), lower cortisol reductions across the day (i.e., less decreasing cortisol slope) and heightened cortisol awakening response (i.e., heightened CAR). Peer non-acceptance and the interaction between peer acceptance and peer non-acceptance (known as peer rejection) were not associated with AUCg, cortisol slope or the CAR. The findings emphasize the association between poor appraisal among classroom peers and children's heightened HPA-axis activation. This underscores the importance of the physiological stress system in studying the consequences of negative peer relations in children.

Children's diurnal cortisol responses to negative events at school and home

This study examined the within-and between-person associations between daily negative events - peer problems, academic problems and interparental conflict - and diurnal cortisol in school-age children. Salivary cortisol levels were assessed four times per day (at wakeup, 30min later, just before dinner and at bedtime) on eight days in 47 youths ages 8-13 years old (60% female; M age=11.28, SD=1.50). The relative contributions of within- and between-person variances in each stressor were estimated in models predicting same-day diurnal cortisol slope, same-day bedtime cortisol, and next morning wakeup cortisol. Children who reported more peer problems on average showed flatter slopes of cortisol decline from wakeup to bedtime. However, children secreted more cortisol at wakeup following days when they had reported more peer or academic problems than usual. Interparental conflict was not significantly associated with diurnal cortisol. Findings from this study extend our understanding of short-term cortisol responses to naturally occurring problems in daily life, and help to differentiate these daily processes from the cumulative effects of chronic stress.

Prolonged perceived stress and saliva cortisol in a large cohort of Danish public service employees: cross-sectional and longitudinal associations

Purpose

It is well known that acute stress can lead to a transient increase in cortisol secretion, but the effects of prolonged stress on cortisol secretion are uncertain. This study examines the cross-sectional and longitudinal associations between prolonged perceived stress and salivary cortisol.

Methods

In 2007, 4467 Danish public service employees participated in a study of stress and mental health, and 3217 participated in a follow-up in 2009. Perceived stress during the past 4 weeks was assessed by Cohen’s four item perceived stress scale. Participants were asked to collect saliva 30 min after awakening and at approximately 20:00 in the evening. The cortisol dependence on perceived stress was examined in regression analyses adjusted for effects of potential confounders. We adjusted for a large variation in saliva sampling times by modelling the time trajectory of cortisol concentrations in the morning and in the evening and examined if they were influenced by perceived stress.

Results

Perceived stress had no statistically significant effects on the level or time trajectory of morning or evening cortisol, neither cross-sectionally nor longitudinally. The 1 month prevalence of frequently perceived stress was low, approximately 2.5%.

Conclusion

Our results did not support the hypothesis that prolonged perceived stress is associated with the level or time trajectory of morning or evening salivary cortisol.

Electronic supplementary material

The online version of this article (doi:10.1007/s00420-017-1241-z) contains supplementary material, which is available to authorized users.

The impact of the severity of early life stress on diurnal cortisol: The role of puberty

Researchers have documented dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis in children and adolescents who experienced early life stress (ELS). The precise nature of this dysregulation, however, has been difficult to discern. In fact, both elevated and blunted patterns of diurnal cortisol regulation have been reported in children and adolescents exposed to greater ELS, including both reduced and heightened cortisol levels and change in cortisol across the day. These divergent findings may be due to developmental changes in the relation between ELS and HPA-axis functioning. The present study was designed to examine the role of puberty in the impact of the severity of ELS on the regulation of diurnal cortisol. Boys and girls (N=145) ages 9-13 years recruited from lower-risk communities completed an interview about their ELS experiences and at-home collection of diurnal cortisol. ELS experiences were objectively coded for severity, and children's level of pubertal development was measured using Tanner Staging. Multi-level piecewise mixed-effects models tested the effects of ELS severity and pubertal stage on cortisol levels at waking, the cortisol awakening response (CAR), and the daytime cortisol slope. While we found no significant interactive effects of pubertal stage and ELS severity on cortisol levels at waking or the daytime cortisol slope, findings indicated that pubertal stage interacted with ELS severity to predict the cortisol awakening response (CAR). Specifically, in earlier puberty, higher ELS was associated with a blunted CAR compared to lower ELS; in contrast, in later puberty, higher ELS was associated with a heightened CAR compared to lower ELS. Differences in the relation between ELS severity and the CAR were uniquely determined by puberty, and not by age. By considering and examining the role of puberty, the current study provides a developmental explanation for previous divergent findings of both blunted and heightened patterns of diurnal cortisol following ELS. These results indicate that careful attention should be given to children's pubertal status before drawing conclusions concerning the nature of diurnal cortisol dysregulation.

Mother-child adrenocortical synchrony; Moderation by dyadic relational behavior

Mother-child adrenocortical synchrony, the coupling of cortisol (CT) secretion in mother and child, has been associated with shared parent-child experiences and maladaptive familial contexts. Yet, few studies tested adrenocortical synchrony in diurnal CT patterns. Guided by the bio-behavioral synchrony model, we examined whether mother-child relational behavior and maternal psychopathology may moderate the degree of concordance between mother and child's diurnal CT. Ninety-seven mothers and their six-year old children participated in two groups; mothers diagnosed with major depression disorder (N=28) and non-depressed controls (N=69). Mother-child interactions were observed and coded for dyadic reciprocity and dyadic tension and diurnal cortisol was collected from mother and child over two consecutive weekend days. Concordance between maternal and child's diurnal CT was found, significant above and beyond time of measurement. Maternal depression, while associated with attenuated child diurnal CT variability, was unrelated to adrenocortical synchrony. Higher child diurnal CT production predicted a stronger linkage between maternal and child's diurnal CT, suggesting that greater child physiological stress is associated with increased susceptibility to the influences of maternal stress physiology. Mother-child reciprocity was related to lower adrenocortical synchrony. Findings suggest that higher adrenocortical synchrony is associated with greater physiological stress and less adaptive dyadic relational patterns. Results raise the possibility that diurnal adrenocortical synchrony taps a unique aspect of HPA-axis functioning whose role in the cross-generational transfer of stress physiology requires further research.

Cortisol profiles differ by race/ethnicity among young sexual minority men

Much of the extant scientific research examining hypothalamic-pituitary-adrenal (HPA)-axis functioning is conducted among White heterosexuals. Very little research examines HPA-axis functioning between different minority groups. Individuals who identify as both sexual and racial minorities may experience increased stigma and discrimination that can affect HPA-axis functioning. In the current study, we examined diurnal cortisol rhythm in young White gay men (WGM) compared to young Black gay men (BGM). The sample consisted of 70 healthy gay men (mean [SD] age=22.9 [3.2]: 68% White and 38% Black) who collected four saliva samples daily for five days. Repeated measures analysis of covariance and post-hoc tests revealed that BGM had higher cortisol levels than WGM in the evening. Secondary analyses revealed no significant group differences for the cortisol awakening response or systemic output throughout the day. However, BGM compared to WGM had a lower drop from peak (morning) to lowest (evening) cortisol concentrations. Taken together, these findings reveal a flatter diurnal cortisol rhythm among BGM compared to WGB. The functional significance of these preliminary findings must be explored further with assessment of psychosocial factors among sexual minorities at the intersection of multiple identities. In summary, we expand health disparities research aimed at delineating sexual minority and race/ethnic variation in stress physiology.

Socioeconomic status, perceived control, diurnal cortisol, and physical symptoms: A moderated mediation model

Social class is a robust predictor of health, with risk for disease and mortality increasing towards the lower end of the socioeconomic (SES) spectrum. While certain psychological characteristics, such as high sense of control, can protect low-SES individuals from adverse health outcomes, very few studies have investigated the biological mechanisms underlying these relationships. In this study, we tested whether sense of control mitigated the associations between SES and cortisol activity, and SES and physical health in daily life (i.e., number and severity of physical symptoms). Next, we tested whether individual differences in cortisol secretion would act as a mechanism by which SES and perceived control influenced physical health. In a large national sample from the Midlife in the United States (MIDUS) survey, we found that SES interacted with perceived control in predicting morning cortisol levels, cortisol slopes, number of physical symptoms, and severity of physical symptoms. Specifically, SES disparities in these health outcomes were more pronounced among individuals reporting low levels of perceived control than among individuals endorsing high levels of perceived control. Further, we found that a flatter cortisol slope mediated the link between lower SES and greater number and severity of physical symptoms for those individuals who reported lower levels of perceived control, but not for individuals reporting higher levels of perceived control. These findings suggest that perception of greater control may act as a buffer against the effect of low SES on health-related physiological processes.

Individual and Day-to-Day Differences in Active Coping Predict Diurnal Cortisol Patterns among Early Adolescent Girls

Prior work has identified alterations in activity of the hypothalamic-pituitary-adrenal axis as a potential mechanism underlying stress-induced emotional health problems, which disproportionately impact girls beginning in mid-adolescence. How adolescent girls differ from one another in dispositional coping tendencies and shift specific coping strategies in response to varying stressors have been theorized as important predictors of their adaptation, health, and well-being during this dynamic period of development. The goal of this study was to examine whether individual and day-to-day (within-person) differences in adolescent girls' coping responses are associated with daily patterns of hypothalamic-pituitary-adrenal axis activity, indexed by cortisol. Participants were 122 early adolescent girls (M _age = 12.39) who provided three saliva samples per day for 3 days and completed daily coping reports, as well as a standard coping survey. Participants and primary caregivers also completed objective life stress interviews. On average, girls who were more likely to respond to interpersonal stress with voluntary engagement (active) coping exhibited generally adaptive daily physiological regulation-steeper diurnal cortisol slopes, lower total diurnal cortisol output, and lower cortisol awakening responses. Chronic interpersonal stress level significantly moderated these associations in different ways for two distinct components of the diurnal pattern-the slope and cortisol awakening responses. Regarding within-person differences, using active coping more than usual was associated with higher waking cortisol the following morning, which may help to prepare adolescent girls for perceived daily demands. These findings highlight the interactive influence of stress and coping in the prediction of daily hypothalamic-pituitary-adrenal axis activity and support the stress-buffering role of active coping for adolescent girls.

Change in parent-child conflict and the HPA-axis: Where should we be looking and for how long?

OBJECTIVE

Salivary cortisol is increasingly used as a longitudinal indicator of change in neuroendocrine regulation and as a predictor of health outcomes in youth. The purpose of this study was to describe which indices of HPA-axis functioning are sensitive to changes in parent-child conflict over a three week period and to explore the time course under which these changes can be measured.

METHODS

Youth (n=47; ages 8-13) completed daily diaries of their conflict with parents for 56 days. On days 17-18 and 38-39, youth contributed saliva samples upon waking, 30-minutes post-waking, afternoon, and bedtime. We assessed change in average diurnal HPA-axis functioning between day 17-18 and day 38-39 as a function of the slopes of change in parent-child conflict over 3 weeks.

RESULTS

Increasing parent-child conflict was positively associated with concurrent increases in total cortisol output (AUCg), flattening of the diurnal slope, and increases in cortisol at bedtime, but not with change in the cortisol awakening response (CAR). Further, associations between parent-child conflict and both AUCg and bedtime cortisol were observed with at least 14 days of daily diary reporting, whereas any additional ratings of conflict beyond 3 days of daily diaries did not improve model fit for changes in diurnal slope.

CONCLUSIONS

This study demonstrates the within-subject up-regulation of the HPA-axis across three weeks in a healthy sample of youth exposed to natural increases in family conflict. In particular, cortisol at bedtime may be the HPA-axis index that is most sensitive to change over time in parent-child conflict, above and beyond conflict occurring that day. Further, when testing associations between family stressors and diurnal cortisol, the optimal schedule for assessing parent-child conflict varies for different indices of HPA-axis functioning.

Emotional attentional control predicts changes in diurnal cortisol secretion following exposure to a prolonged psychosocial stressor

Hypothalamic-pituitary-adrenal (HPA) axis irregularities have been associated with several psychological disorders. Hence, the identification of individual difference variables that predict variations in HPA-axis activity represents an important challenge for psychiatric research. We investigated whether self-reported attentional control in emotionally demanding situations prospectively predicted changes in diurnal salivary cortisol secretion following exposure to a prolonged psychosocial stressor. Low ability to voluntarily control attention has previously been associated with anxiety and depressive symptomatology. Attentional control was assessed using the Emotional Attentional Control Scale. In students who were preparing for academic examination, salivary cortisol was assessed before (time 1) and after (time 2) examination. Results showed that lower levels of self-reported emotional attentional control at time 1 (N=90) predicted higher absolute diurnal cortisol secretion and a slower decline in cortisol throughout the day at time 2 (N=71). Difficulty controlling attention during emotional experiences may lead to chronic HPA-axis hyperactivity after prolonged exposure to stress. These results indicate that screening for individual differences may foster prediction of HPA-axis disturbances, paving the way for targeted disorder prevention.

Temporal patterns, heterogeneity, and stability of diurnal cortisol rhythms in children with autism spectrum disorder

The current study used a multifaceted approach to assess whether children with ASD have a distinctive diurnal rhythm of cortisol that differentiates them from typically developing (TD) peers and whether sub-groups of ASD children can be identified with unique diurnal profiles. Salivary cortisol was sampled at four time points during the day (waking, 30-min post-waking, afternoon, and evening) across three days in a sample of 36 children with autism spectrum disorder (ASD) and 27 typically developing (TD) peers. Between-group comparisons on both mean levels and featural components of diurnal cortisol indicated elevated evening cortisol and a dampened linear decline across the day in the ASD group. No differences were evident on the cortisol awakening response (CAR). Group-based trajectory modeling indicated that a subgroup (25%) of ASD children demonstrated an attenuated linear decline while the cortisol trajectory of the second subgroup was indistinguishable from that of the TD group. Intraclass correlations indicated that, when aggregated across days, cortisol measures were generally stable over the interval assessed. There were few significant relations between cortisol measures or sub-groups and measures of stress, temperament, and symptoms. Results encourage follow-up studies to investigate the functional significance, heterogeneity and longer-term stability of diurnal cortisol profiles in children with ASD.

Life satisfaction moderates the impact of socioeconomic status on diurnal cortisol slope

The association between SES and health is well established; however, only a handful of studies have investigated the relationship between SES and daily cortisol parameters. Further, within this small literature, virtually no studies have looked at psychological factors that might mitigate this relationship. In this study, we tested whether life satisfaction--the overall subjective affective assessment of one's own life--acts as a protective factor against cortisol dysregulation driven by low-SES. Among a large sample (N=1325) of individuals from the Midlife in the United States (MIDUS) survey, we found that low-SES individuals with high levels of life satisfaction had a cortisol circadian profile similar to those of high-SES individuals. In contrast, low-SES individuals reporting low life satisfaction experienced attenuated morning cortisol concentrations and a flatter ("less healthy") diurnal cortisol slope. Although more studies are needed to investigate the constellation of psychological resources and processes through which life satisfaction exerts its effects, the current work shows that the general affective evaluation of one's own life acts as a buffer against the detrimental effect of low-SES on health-related physiological processes.

Longitudinal associations between diurnal cortisol slope and alcohol use across adolescence: a seven-year prospective study

A large body of research has linked hypothalamic-pituitary-adrenal (HPA) axis function and alcohol consumption, including work suggesting that flatter diurnal cortisol slopes are associated with greater alcohol use. A lack of longitudinal studies and a focus on adult and alcoholic populations leaves unclear whether such associations are also present in younger, non-clinical populations and whether flatter diurnal slopes are a consequence of or preexisting risk factor for alcohol use; however, theory suggests such associations may be mutually reinforcing. In a longitudinal, community sample of 200 (55% female) adolescents, the current study demonstrates that flatter diurnal cortisol slope at age 11 predicts higher levels of alcohol use from ages 15-18, and that heavier alcohol use in turn predicts further flattening of diurnal cortisol rhythm at age 18.5. This is the first study to demonstrate a longitudinal chain of associations between diurnal cortisol slope and alcohol use. Findings support contemporary theoretical models of the neurobiological processes underlying alcohol use and can inform future research on risk factors for and consequences of underage drinking.

Perceived appearance judgments moderate the biological stress effects of social exchanges

Social relationships are generally thought of as beneficial. However, the present study set out to test the hypothesis that for individuals who perceive others to judge their appearance negatively, daily social interactions can also be a source of stress. Indeed when assessing 38 young adults, we found that both more incidences of negative exchanges reported during the past month as well as perceived negative appearance judgments by others were associated with more self-reported stress. Interestingly, however, for individuals with low attribution body esteem, higher numbers of positive social exchanges during the past month were related to health-relevant changes in biological markers of chronic stress as well. The same was true for individuals with high attribution body esteem who reported to experience only very few positive exchanges. As such, these findings go beyond the initial focus on low body esteem and negative social exchanges and introduce high body esteem as well as daily positive exchanges as potential health risk factors.

Associations between self-reported discrimination and diurnal cortisol rhythms among young adults: The moderating role of racial-ethnic minority status

Discrimination is theorized to set in motion a neuroendocrine response, which includes cortisol secretion from the hypothalamic-pituitary-adrenal axis. Repeated exposure to perceived discrimination is thought to contribute to alterations in diurnal cortisol rhythms and to have implications for health. Discrimination may have particularly strong effects on racial/ethnic minority individuals, based on histories of past exposure and/or greater perceived implications of discriminatory events. Utilizing an ethnically and racially diverse sample of young adults (N=140; Mage=22.8 years) and a multiple-day naturalistic cortisol protocol, the present study examined associations between self-reported discrimination and diurnal cortisol rhythms, and whether this relation was moderated by racial/ethnic minority status. Results revealed that self-reported discrimination predicted flatter diurnal cortisol slopes for racial/ethnic minority individuals only. These findings align with theory suggesting that discrimination experiences are important among racial/ethnic minorities.

stretching on diurnal cortisol dynamics and psychosocial outcomes in individuals with the metabolic syndrome: the PRYSMS randomized controlled trial

PURPOSE

Chronic stimulation and dysregulation of the neuroendocrine system by stress may cause metabolic abnormalities. We estimated how much cortisol and psychosocial outcomes improved with a restorative yoga (relaxation) versus a low impact stretching intervention for individuals with the metabolic syndrome.

METHODS

We conducted a 1-year multi-center randomized controlled trial (6-month intervention and 6-month maintenance phase) of restorative yoga vs. stretching. Participants completed surveys to assess depression, social support, positive affect, and stress at baseline, 6 months and 12 months. For each assessment, we collected saliva at four points daily for three days and collected response to dexamethasone on the fourth day for analysis of diurnal cortisol dynamics. We analyzed our data using multivariate regression models, controlling for study site, medications (antidepressants, hormone therapy), body mass index, and baseline cortisol values.

RESULTS

Psychosocial outcome measures were available for 171 study participants at baseline, 140 at 6 months, and 132 at 1 year. Complete cortisol data were available for 136 of 171 study participants (72 in restorative yoga and 64 in stretching) and were only available at baseline and 6 months. At 6 months, the stretching group had decreased cortisol at waking and bedtime compared to the restorative yoga group. The pattern of changes in stress mirrored this improvement, with the stretching group showing reductions in chronic stress severity and perseverative thoughts about their stress. Perceived stress decreased by 1.5 points (-0.4; 3.3, p=0.11) at 6 months, and by 2.0 points (0.1; 3.9, p=0.04) at 1 year in the stretching compared to restorative yoga groups. Post hoc analyses suggest that in the stretching group only, perceived increases in social support (particularly feelings of belonging), but not changes in stress were related to improved cortisol dynamics.

CONCLUSIONS

We found significant decreases in salivary cortisol, chronic stress severity, and stress perception in the stretching group compared to the restorative yoga group. Group support during the interactive stretch classes may have contributed to these changes.

Approach and avoidance coping: diurnal cortisol rhythm in prostate cancer survivors

Psychological coping responses likely modulate the negative physiological consequences of cancer-related demands. This longitudinal, observational study examined how approach- and avoidance-oriented strategies for coping with cancer are associated with diurnal cortisol rhythm in prostate cancer (PC) survivors. Sixty-six men (M age=65.76; SD=9.04) who had undergone radical prostatectomy or radiation therapy for localized PC within the prior two years reported their use of approach and avoidance coping via questionnaire at study entry (T1). Participants provided saliva samples (3 times per day over 3 days) for diurnal cortisol assessment at T1 and again 4 months later (T2). When controlling for relevant biobehavioral covariates, cancer-related avoidance-oriented coping was associated with flatter cortisol slopes at T1 (B=.34, p=.03) and at T2 (B=.30, p=.02). Approach-oriented coping was not associated with cortisol slopes. Post-hoc analyses revealed a significant interaction between avoidant coping and time since completion of cancer treatment on T2 cortisol slope (B=-.05, p=.04). Men who used relatively more avoidance-oriented coping who were further in time from treatment demonstrated a flatter cortisol slope. High avoidance-oriented coping is associated with dysregulation of cortisol responses, which may be an important target for reducing stress during PC survivorship.

Posttraumatic growth and diurnal cortisol slope among women with metastatic breast cancer

BACKGROUND

A cancer diagnosis leads to increased psychological and emotional distress. However, in the aftermath of a traumatic event, such as being diagnosed with breast cancer, an individual may also experience beneficial changes in life perspective, relationships with others, and more. These changes are collectively known as posttraumatic growth (PTG). Studies have demonstrated that cortisol levels have been linked with cancer survival, yet an investigation of the relationship between PTG and cortisol has yet to be conducted among cancer patients.

METHODS

The relationship of PTG to cortisol levels was examined among 99 metastatic breast cancer patients.

RESULTS

We found a significant correlation between PTG and diurnal cortisol slope (Spearman's rho=-0.21, p<0.05), indicating a link between positive psychological changes and healthier endocrine functioning in cancer patients.

CONCLUSIONS

PTG in response to the stress of cancer was related to more normal (i.e., steeper) diurnal cortisol patterns. Longitudinal studies are recommended to investigate these mechanisms in relationship to cancer survival.

Salivary cortisol protocol adherence and reliability by socio-demographic features: the Multi-Ethnic Study of Atherosclerosis

Collection of salivary cortisol has become increasingly popular in large population-based studies. However, the impact of protocol compliance on day-to-day reliabilities of measures, and the extent to which reliabilities differ systematically according to socio-demographic characteristics, has not been well characterized in large-scale population-based studies to date. Using data on 935 men and women from the Multi-Ethnic Study of Atherosclerosis, we investigated whether sampling protocol compliance differs systematically according to socio-demographic factors and whether compliance was associated with cortisol estimates, as well as whether associations of cortisol with both compliance and socio-demographic characteristics were robust to adjustments for one another. We further assessed the day-to-day reliability for cortisol features and the extent to which reliabilities vary according to socio-demographic factors and sampling protocol compliance. Overall, we found higher compliance among persons with higher levels of income and education. Lower compliance was significantly associated with a less pronounced cortisol awakening response (CAR) but was not associated with any other cortisol features, and adjustment for compliance did not affect associations of socio-demographic characteristics with cortisol. Reliability was higher for area under the curve (AUC) and wake up values than for other features, but generally did not vary according to socio-demographic characteristics, with few exceptions. Our findings regarding intra-class correlation coefficients (ICCs) support prior research indicating that multiple day collection is preferable to single day collection, particularly for CAR and slopes, more so than wakeup and AUC. There were few differences in reliability by socio-demographic characteristics. Thus, it is unlikely that group-specific sampling protocols are warranted.

Relationship between the cortisol awakening response and other features of the diurnal cortisol rhythm: the Multi-Ethnic Study of Atherosclerosis

Cumulative cortisol burden is known to influence neuropsychiatric and metabolic disorders. To better understand the relationship between daily cortisol exposure and measures of the diurnal circadian cortisol rhythm, we examined the cross-sectional association of the cortisol awakening response (CAR) with wake-up cortisol, bedtime cortisol, diurnal slope, and total cortisol area under the curve (AUC). Up to 18 salivary cortisol samples were collected over 3 days from 935 White, Hispanic, and Black individuals (mean age 65 ± 9.8 years) in the Multi-Ethnic Study of Atherosclerosis. Outcome measures included awakening cortisol, CAR (awakening to 30 min post-awakening), early decline (30 min to 2h post-awakening), late decline (2h post-awakening to bedtime), and the corresponding AUCs. Total cortisol AUC was a summary measure of cumulative cortisol exposure. Higher CAR was associated with significantly lower wake-up cortisol (β=-0.56; 95% CI: -0.59 to -0.53) and a higher early decline AUC (β=0.38; 95% CI: 0.34-0.42) but was not associated with total cortisol AUC (β=0.04; 95% CI: -0.01 to 0.09), or other diurnal cortisol curve components following multivariable adjustment. Total cortisol AUC was significantly and positively associated with wake-up cortisol (β=0.36; 95% CI: 0.32-0.40), bedtime cortisol (β=0.61; 95% CI: 0.58-0.64), and other AUC measures, following multivariable adjustment. Associations were similar by sex, race/ethnicity, and age categories. We conclude that bedtime cortisol showed the strongest correlation with total cortisol AUC, suggesting it may be a marker of daily cortisol exposure.